Published 4:00 am, Saturday, September 3, 2005

2005-09-03 04:00:00 PDT Vienna -- Despite an intense 2 1/2-year investigation, key elements of Iran's nuclear program remain shrouded in mystery, according to a report by the International Atomic Energy Agency, the U.N. nuclear watchdog.

The confidential report, distributed Friday to members of the IAEA's board, is likely to heighten tensions between Iran and the West. While it casts some new light on suspicious uranium contamination at Iranian nuclear sites, the report mostly summarizes Iran's reluctance to resolve questions about its acquisition of nuclear equipment and activities at several nuclear facilities.

The report also confirmed that Iran has begun processing nuclear fuel, ending a voluntary suspension of such activity during talks about its program with Britain, France and Germany. This was expected; Iran said last month it would no longer abide by the suspension.

The Bush administration and the three European nations have tried, so far without success, to get a consensus on the IAEA board supporting referral of Iran to the U.N. Security Council to consider imposing sanctions tied to its nuclear program. Friday's report appeared to fall short of the kind of critical declaration that American and European officials said they would be looking for. European officials hold out hope for a revival of talks with Iran, though they, too, are frustrated.

"Two and a half years have passed, and patience is wearing thin," said an official close to the agency, who spoke on condition of anonymity because the report was not being made public.

Bush administration officials in Washington said they were still analyzing the report. Earlier in the week, however, some officials expressed hope the report would contain enough concrete evidence of Iranian misconduct to persuade wavering members of the agency's board of governors to censure Iran when they meet on Sept. 19, and to refer the questions about its nuclear program to the Security Council.

Diplomats have been eagerly awaiting the report by the agency's director general, Mohamed ElBaradei. A copy was provided by a diplomat who wanted its contents made public before the board meets.

The document does disclose mounting frustration within the agency about its inability to get answers to questions, despite repeated requests and visits to Iran by its inspectors. Departing from its carefully neutral tone, it concludes, "In view of the fact that the agency is not in a position to clarify some important outstanding issues after two and a half years of intensive inspection and investigation, Iran's full transparency is indispensable and overdue."

Among the mysteries is how Iran first obtained centrifuge machines, which are used to enrich uranium. The Iranian government gave the agency a one-page handwritten document that it said related to an offer it received in 1987 of blueprints and components for 2,000 centrifuges. Despite requests, Iran has not produced any other documentation about this offer, which it said came from a foreign intermediary.

The agency also cannot determine whether Iran was conducting nuclear research at a site in Tehran called Lavisan-Shian, which was demolished in 2004. The agency would like to interview scientists who worked there.

Iran continues to resist the IAEA's efforts to conduct a full inspection of a site in Parchin, where Iran is suspected of nuclear activities. Inspectors have been permitted to visit only limited areas on the site, where they have not detected nuclear material.

The agency said there were also discrepancies in information provided by Iran about its plutonium research. Plutonium, like highly enriched uranium, can be used to make nuclear explosives.

Iran, which contends its nuclear program is peaceful, said the report had both "positive and negative points." Pledging to cooperate with the agency, Iran's top nuclear negotiator, Ali Larijani, said Friday on state television, "Many of the questions have been answered from a legal and technical point of view."

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